Last name Nikolaï (Николай 
, Nikolai 
, Nikolaï 
) , in the world, is a common cognomen. The surname Nikolaï is habitual in Kyrgyzstan, where it is a common surname, Bulgaria, where it is quite a common surname, and Armenia (explore the name in all countries). Measured by absolute frequency, this name is the most popular in Russia, Kyrgyzstan, and Bulgaria. Much more prevalently, Nikolaï is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Николай | Ukraine, Kazakhstan, Belarus, Russia, Kyrgyzstan |
| Nikolai | Moldova, Germany, Bulgaria, Russia, Kyrgyzstan |
| Nikolaï | Russia, France, Italy |
| ニコライ | Japan |
Mikalai, Mikalaj, Mikalay, Mikałaj, Miklavž, Miklos, Miklós, Mikola, Mikołaj, Mikuláš, Mikławš, Mykola, Mykoła, Niccolò, Nicholas, Nickel, Nicolaas, Nicolae, Nicolaes, Nicolai, Nicolas, Nicolau, Nicolay, Nicolino, Nicolo, Nicolás, Nicolò, Nicos, Nicu, Niels, Nikolai, Nikolaj, Nikolaj, Nikolajs, Nikolajus, Nikolao, Nikolaos, Nikolas, Nikolass, Nikolaus, Nikolay, Nikolaz, Nikolos, Nikoloz, Nikos, Nikołaj, Nikulás, Nils, Nyikolaj, Νίκολας, Νίκος, Νικολάου, Νικόλαος, Νικόλας, Коля, Микалай, Миклош, Микола, Миколай, Микулаш, Мыкола, Мікалай, Міклаш, Мікола, Никель, Никколо, Никола, Николае, Николаев, Николаз, Николайс, Николаос, Николас, Николау, Николаус, Николаэ, Николо, Николоз, Николя, Никос, Нилс, Нильс, Нікалас, Нікало, Ніколай, Ніколас, Нільс, נילס, ניקולאו, ניקולאי, ניקולס, نيقولا, نيقولاي, نيكوس, نيكولاس, نيكولاي, نيلز, نيلس, ნიკოლასი, ნიკოლოზ, ニコラ, ニコラウス, ニコラス, ニルス, 尼克斯, 尼古拉, 尼古拉斯, 尼古拉耶夫, 尼尔斯, and 니콜라
Maire, Retamal, Sitnikov, Stavroguine, Khartchenko, Krawczyk, Grachyov, Lieutier, Roycourt, Tikhonchuk, Nersesyan, Senczyszyn, Stetsenko, Avgerinos, Kazimirov, Witkovich, Berezovski, Nowatschok, Primeon, Blaskov, Sosiewicz, Mocle, Sheen, Smith, Reiss, Houde, Feron, Ospel, Sagner, Koroye, Posner, Ivanov, Owedyk, Marinov, Makarov, Morozov, Salzard, Saoulski, Kratchkovsky, and Vassilieff